Is a gateway just a gateway, or can it be used as a standalone a device? If the latter, are all devices Ethernet-enabled? This would be a waste of hardware, right? If not, are the devices with Ethernet also devices on their own, allowing someone to have just one device? Would they ever have just one device?

And if they did, would this be better than a USB device? It would work even with the computer down, right?

I can see that I should do some fundamental architecture decisionmaking. I need to rank all the desired features, and see what is the best solution both short and long term.

Desired features, advantages and disadvantages

1. plug and play, no drivers: Ethernet, or USB as flash drive
2. USB: no power conn needed
3. Ethernet: no USB; power conn needed
4. radio: all devices have
5. local computer control (no internet needed): USB or Ethernet
6. Ethernet-internet control (no local computer needed): Ethernet

Proposed architecture

1. Ethernet
2. Simple power conn (switching supply for efficiency)
3. Radio

Could all devices have both ethernet and radio? This would mean, from a both Zigbee and an aiosphere network perspective, that they should be able to be both net master/gateway.

I know from looking at some of the common Zigbee modules that this is not as easy as simply having fixed roles. So, for my first system draft, I think I will take the easy route and have some devices, which cost more, which are gateways, and others which are simple radio devices.

Next decision: do I make the gateway be a device, itself? On the one hand, this is attractive, as in my system there are no ugly appliances, only interesting and useful objects. On the other, it would mean that I would either need to force all users to have one particular type of device as their gateway device, or offer a range of devices with gateway capability.

To have a single gateway, which does nothing else, would tend to help avoid a situation where a user would plug more than one gateway in (because they both have desired features). Which would avoid my having to have some complex negotiation between two gateways, to decide which would act as a gateway and which would act as a simple device, ignoring its gateway capability.